Polish UI components and rework AgentConfigForm

Major AgentConfigForm rework with improved adapter configuration
fields and layout. Refine sidebar, breadcrumbs, and card/tab
components for visual consistency. Clean up page layouts across
Activity, Agents, Approvals, Costs, Dashboard, Goals, Inbox,
Issues, Org, and Projects pages. Minor heartbeat-run CLI fix.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

ui/src/components/SidebarNavItem.tsx

@@ -23,10 +23,10 @@ export function SidebarNavItem({
       end={end}
       className={({ isActive }) =>
         cn(
-          "flex items-center gap-2 px-3 py-1.5 rounded-md text-sm font-medium transition-colors",
+          "flex items-center gap-2.5 px-3 py-2 text-[13px] font-medium transition-colors",
           isActive
-            ? "bg-accent text-accent-foreground"
-            : "text-muted-foreground hover:bg-accent/50 hover:text-accent-foreground"
+            ? "bg-accent text-foreground"
+            : "text-foreground/80 hover:bg-accent/50 hover:text-foreground"
         )
       }
     >